hmmm...
kike is derived from the hebrew word for circle, which is the mark many jews made on their immigration papers coming into america (instead of an "x" for their signature). like many other racial slurs, it came from immigration officers who used it as short-hand for a population group entering the country.

A racial slur for a Jewish person. Originates from the word 'keikl', in Yiddish, which means 'circle', the reason being that the first Jewish immigrants in America, who were unable to sign their names, signed with a circle instead of a cross.